package jdk.collection;

import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;

public class TreeMapDemo {

    public static void main(String[] args) {
        TreeMap map = new TreeMap();
        map.put(3, "three");
        map.put(2, "two");
        map.put(1, "one");
        map.put(4, map);
        map.put(7, new HashMap());
        System.out.print(map);
    }
}


